1. Field of the Invention
The invention relates to powder inhalers in which the powder used for inhalation is placed in readiness on carriers having specific regular microstructures.
2. Background Art
Of the numerous types of devices for powder inhalation which have already been described, there are some with belt-shaped carriers (WO 90/13328). Such carriers may have very different surface structures, e.g. conical depressions stamped into plastics film for holding the powder, or they may consist, for example, of woven or non-woven (fleece-like) fibrous material in which the powder is incorporated between the fibres or in gaps in the fabric.